1. Field of the Invention
The invention relates to a touch panel, and more particularly, to a capacitive touch panel.
2. Description of Related Art
With the rapid development of technology, most electronic devices, such as notebook computers, mobile phones or portable multimedia players, usually adopt touch panels as input interfaces. Touch panels are generally categorized into capacitive touch panels and resistive touch panels. The capacitive touch panels are operated by approaching or touching the touch panels with a finger or a conductive material to change capacitances of the touch panels. When the variation in capacitance values is detected, the location approached or touched by the finger or conductive material can be identified to further execute a predetermined operation corresponding to the foregoing approached or touched location.
FIG. 1 shows a conventional touch panel and illustrates a schematic diagram of peak positions when a user touches a position A and a position B simultaneously. As shown in FIG. 1, a conventional touch panel includes a plurality of panel capacitors, for example, panel capacitors C11-C15. When the touch panel detects a touched position, panel capacitance values corresponding to the X-axis and the Y-axis are scanned by the touch panel respectively. Accordingly, when the position corresponding to the panel capacitances is touched, the panel capacitances generate corresponding capacitance change. At this time, the touched position can be positioned by intersecting the peak positions corresponding to different axes.
However, when the user touches the position A and the position B simultaneously, the position A touched and the position B touched each generate two peaks, for example, X2, X5, Y3, and Y5, at the X axis and the Y axis. At this time, the peaks on the two axes intersect to generate four intersection points, for example, A, B, A′, and B′. Here, the two intersection points A′ and B′ that are not the actual touched positions are referred as ghost points. In this case, the touch panel detects false touched positions and causes operational error as a consequence.